WASHINGTON  It's easy to understand why Congress is having so much trouble settling on an approach to immigration: Americans endorse the most controversial proposals of both those who want to penalize illegal immigrants and those who want to let them stay.

A USA TODAY/Gallup Poll taken Friday through Sunday found a majority of those surveyed want to make it a crime for foreigners to immigrate illegally to the USA and for Americans to help those illegal immigrants once they arrive.

Still, nearly two-thirds also say the government should allow illegal immigrants to remain and become U.S. citizens if they meet certain requirements over time.

"The same problems that bedevil Congress in trying to figure out how to handle immigration are bedeviling the American psyche and the American public in trying to deal with it," says Frank Newport, editor in chief of the Gallup Poll. "There's no easy solution, as Congress has discovered, and I think the public holds these same almost-contradictory attitudes about immigration."

That means the debate being waged in the halls of Congress and at rallies across the country Monday could shape public opinion and, with it, public policy.

LeRoy Gomez, 58, a part-time union representative from Fort Collins, Colo., who was among those surveyed, says the rallies have been inspiring for many Latinos — including those, like himself, whose families have been in the USA for generations. "They want to be part of the American dream," he says of the marchers.

Linda Martin, 56, a private investigator from Visalia, Calif., says the rallies she watched on TV only reinforced her view that tough measures need to be taken to deal with illegal immigrants.

"If they've come here illegally, then they all ought to be sent back," she says. Of the children shown marching, she says, "A lot of them are just doing it to get out of school."

There is nearly universal agreement on one point: The system needs fixing.

Eight in 10 say illegal immigration to the USA is "out of control." More than nine in 10 say it's important for the government to take steps this year to control the borders and deal with those illegal immigrants who already are here. The feelings about border security are particularly intense.

Yet most Americans are pessimistic about whether that effort could ever succeed.

Six in 10 say that no matter what the government does, a "sizable number" of illegal immigrants will be able to get into the country.

William Gretler, 77, of Shell Lake, Wis., worries about undocumented workers taking jobs from Americans and creating burdens for taxpayers. "The local government has to pick up their medical care, the school system has to pick up their schooling and health care systems have to pick up the price for helping keep them alive," the retired steelworker says.

On the other hand, he doesn't like the idea of forcing them to return to their home countries. "I can't see splitting up families," Gretler says, and he thinks it's "crazy" to penalize those who try to help them. The bill passed by the House of Representatives in December would make it a crime to assist illegal immigrants.

Joshua Akers, 22, a grocery-store stocker in Columbia, S.C., feels little of Gretler's ambivalence toward illegal immigrants. "I think they should be deported if they can't meet certain guidelines," he says, including having a family member who lives in the USA and already is a citizen. "They know it's wrong to come across the border and they do it anyway, which is not right."

There are close divisions over one of the most drastic proposals: building a wall. The House bill includes plans for a 700-mile fence along the U.S.-Mexican border where illegal crossings are most common.

By 48%-49%, Americans split over whether that would be effective in curbing the number of people who come here illegally.

Layne Sanders, 42, of Oakland, supports setting a cutoff date to prevent a new wave of illegal immigrants from taking advantage of any program enacted to make current ones legal. But erecting a wall is "going a little far," he says. "It's just a little too East/West Germany for my taste."

Most useful, according to those polled, would be instituting tough penalties for businesses that employ illegal immigrants; 84% call that an effective step. A similar number say that significantly increasing the number of law-enforcement officers patrolling the border would help.

By more than 2-1, they say taking steps to raise the standard of living in the immigrants' home countries would be effective, too.

"Different polls have reached different conclusions, but a common thread has been that Americans are concerned about the lack of enforcement along our borders, and rightly so," says Sen. John Cornyn, R-Texas. He opposes a bipartisan Senate plan — crafted last week but then ensnared in procedural roadblocks — that would allow illegal immigrants in the USA for more than five years to stay here and move toward citizenship.

Sen. Edward Kennedy, D-Mass., says Americans "know that our immigration system is broken and are demanding that Congress take action." He helped draft the Senate plan. "The only way to break the cycle of illegality is to offer a path for earned legalization."

Views on immigration differ depending on where Americans live, how much education they have — and whether their family includes a recent immigrant.

In Sara Brodsky Sieman's family, her grandparents emigrated from Lithuania and Russia, her father from Ukraine. "People come here, as they did in all the generations before us, to help the people back home, and I think that's a very important thing to remember," says Sieman, 53, a ballroom-dance instructor from Newton, Mass. "I'd like to bring people into the civic and economic life of our country, and make for them what I hope would be a more productive life and a less scary life."

When it comes to whether illegal immigrants should be able to stay in the USA and become citizens:

• Those who are immigrants or have at least one parent who is an immigrant are more likely to support the idea; 71% do so, compared with 62% among those whose parents were native-born.

• Among Democrats, 68% support citizenship for illegal immigrants, as do 65% of independents. Among Republicans, a 55% majority endorse the idea.

• By region, those in the West are most favorable, at 67% support. Those in the Midwest are least supportive, at 57%.

• Women are more supportive than men, 67% vs. 58%.

Some conservatives questioned those findings. "If you mention 'amnesty,' you tend to get much different numbers," says Will Adams, a spokesman for Rep. Tom Tancredo, R-Colo., who is leading the fight against legalization.

Lawmakers such as Kennedy who favor allowing illegal immigrants to stay deny their proposal is "amnesty" because it includes fines and other requirements.

Personal connections

Just more than one-third of those surveyed say they know a recent immigrant who they are sure is here illegally, or think may be.

Those relationships have tempered the views of James Stoddard, 52, of Santa Maria, Calif. On one hand, the salesman questions whether the children of illegal immigrants born in the USA should be granted citizenship, as they are now. On the other, he says the undocumented workers he knows personally are "good people" and "hard-working."

He adds, "Some of the ones I know I would love to have stay."

Carolyn Long, 62, a retired insurance manager from Alpharetta, Ga., says she doesn't know the legal standing of workers she sees in her neighborhood. "We have a lot of Mexicans that work ... here for the landscaping businesses, and I have no idea if they're illegal or not," she says.

In any case, her view is unyielding: "Any illegal immigrants need to be sent back to wherever they're from, and then they need to come through whatever the correct way is."

Fewer than one in five Americans think all illegal immigrants — a group estimated at as many as 12 million, equal to the population of Ohio — should be deported. A similar number say they should be allowed to stay and work for a limited amount of time.

Instead, a significant majority, 63%, say there should be a way for illegal immigrants to stay here and become citizens if they meet certain requirements.

More than eight in 10 say those requirements should include:

• Having a job.

• Learning to speak English.

• Passing a health screening.

• Paying federal taxes due on past income.

Two-thirds say illegal immigrants should be required to have lived in the United States for at least five years and pay a fine for coming to the USA illegally.

The politics of immigration is tricky, particularly in a year when control of the House and Senate could be at stake in November.

Both Democrats and Republicans have powerful constituencies that favor the Senate deal, which provides for a program to expand the number of foreign temporary, or guest, workers and legal status for most illegal immigrants. They include the U.S. Chamber of Commerce and businesses that rely on immigrant labor, some unions that would like to organize those workers and civil-rights groups. President Bush has called for bringing illegal immigrants "out of the shadows."

Both parties also have powerful constituencies that oppose the Senate proposal, however. Cornyn has been inundated with calls and mail from constituents who oppose what they see as "amnesty" for lawbreakers, the senator's spokesman, Don Stewart, says. Some African-Americans worry that illegal immigrants will hold down wages or take jobs from American-born workers.

A prized voting bloc

And neither party wants the other to get credit for passing a bill that has ignited passions among one of the nation's fastest growing and most prized voting blocs, the nation's 9.3 million Hispanic voters.

On Monday, Senate Majority Leader Bill Frist, R-Tenn., and Minority Leader Harry Reid, D-Nev., issued dueling news releases blaming the other for the failure to pass a bill before Congress left town on a two-week break for Easter and Passover.

Tancredo, nationally known as a spokesman against illegal immigration, is considering a dark-horse run for the White House in 2008 as a way to highlight his concerns.

But many of the leading GOP presidential hopefuls are on the other side of the issue. Sens. John McCain of Arizona, Sam Brownback of Kansas and Chuck Hagel of Nebraska were architects of the Senate plan. After initially withholding his support, Frist also embraced the proposal.

Bush favors "comprehensive" reform, including tougher enforcement and a guest-worker program. In the USA TODAY poll, just 29% say they approve of his handling of immigration; 62% disapprove.

That dismal rating reflects the public's "frustration" with the lack of progress on immigration reform, says Rep. Henry Bonilla, a Republican whose Texas district borders Mexico. "I think the public wants to see results," he says.